1. Field of the Invention
The present invention relates to a bookbinding apparatus for placing a sheet with an image formed thereon on a tray and binding a bundle of placed sheets, and to an image formation processing system provided with such bookbinding means.
2. Description of Related Art
In a conventional bookbinding apparatus for image formed sheets, a plurality of sheets is gathered in the shape of a bundle to form a sheet bundle, an adhesive is applied to one end face of the formed sheet bundle, and a front cover is bonded to the end face of the sheet bundle applied with the adhesive. Further, the bookbinding apparatus is usually provided with a cutting portion that cuts the end face of the sheet bundle to a predetermined size, and a storage portion that stores bound sheet bundles while stacking the bundles (for example, see Patent Documents 1 and 2).
Further, an image formation processing system has conventionally been known for forming an image on a sheet, placing the sheet with the image formed thereon on a tray, and performing the aforementioned bookbinding processing on a bundle of placed sheets. As an example of such an image formation processing system, Patent Document 3 discloses an image formation processing system integrally provided with an image formation portion that forms an image and transfers the image to a sheet, a post-processing portion that performs predetermined post-processing on the sheet with the image transferred in the image formation portion, and a gluing processing portion that performs gluing processing on the sheet with the image transferred thereto.
[Patent Document 1] JP2001-240301
[Patent Document 2] JP2002-326473
[Patent Document 3] U.S. Pat. No. 5,540,421
However, in such a conventional bookbinding apparatus, the sheet bundle is conveyed in various directions and bound. More specifically, for example, the sheet bundle is conveyed while lying (in the direction along the end face of the sheet bundle), and/or conveyed in an oblique direction, thereby achieving application of adhesive, cutting and storage. Therefore, various problems have occurred as described below.
When a sheet bundle is conveyed in various directions such as vertical, horizontal and oblique directions in the bookbinding apparatus, the need arises for securing space to convert a posture of the sheet bundle in the bookbinding apparatus, and further, an area increases occupied by transport paths for sheet bundles in the bookbinding apparatus. In other words, it is necessary to secure a large volume of space for transport paths of sheet bundles in the bookbinding apparatus, and the bookbinding apparatus is increased in size, resulting in a problem of increasing manufacturing cost of the bookbinding apparatus.
Further, when an adhesive is applied to an end face of a sheet bundle in a state where the sheet bundle is lying (horizontal state), the adhesive needs to be applied from the side to the end face of the sheet bundle, and it is required to improve the structure to apply the adhesive uniformly with excellence. For example, when an adhesive is applied from the side to the end face of the sheet bundle from an adhesive applying device provided with a container that stores the adhesive, in order to prevent the adhesive to apply from leaking from the container due to the effect of gravity, it is necessary to provide the container with a sealing structure. Therefore, the adhesive applying device in the conventional apparatus has been complicated in structure.
Furthermore, in conveying the sheet bundle applied with the adhesive while letting the sheet bundle lie, when the sheet bundle has been applied with a large amount of the adhesive, or conveyed while being inclined, there is the fear that such a problem may occur that the end face of the sheet bundle comes into contact with various members including a side wall of the transport path while being conveyed, and the adhesive coated on the end face of the sheet bundle is thereby removed. In order to prevent such a problem, devices are considered such as securing sufficient space between the end face of the sheet bundle applied with the adhesive and the transport path, and providing specific equipment for precisely controlling an application amount of the adhesive. However, these cases result in increases in size and cost of the apparatus.
Moreover, when an adhesive is applied to a sheet bundle, a front cover is bonded thereto, and the end face of the sheet bundle is cut while letting the sheet bundle lie, since the direction (vertical direction) in which the adhesive spills and drips from the front cover due to gravity agrees with the direction in which a cutting blade moves, the spilled adhesive is apt to adhere to the cutting blade, and there has been the fear that the adhered adhesive degrades subsequent cutting function of the cutting blade.
Further, in the case of storing bound sheet bundles while letting the bundles lie (horizontal state), since the direction (vertical direction) in which the adhesive drips due to gravity agrees with the direction in which the sheet bundles are stacked, such a problem has occurred that the dripped adhesive bonds sheet bundles.
Furthermore, in the image formation processing system as described in Patent Document 3, transport paths are provided to convey a sheet between processing portions. However, a transport path to convey a sheet from the image formation portion to the gluing processing portion is provided independently of a transport path to convey a sheet from the image formation portion to the post-processing portion via the gluing processing portion, and further, a transport path for a sheet to undergo processing in the gluing processing portion functions independently of a transport path for a sheet to undergo processing in the post-processing portion. Therefore, transport paths are complicated, and the ratio of transport paths occupying in the space is large in the apparatus. Thus, in the conventional system, the internal mechanism is complicated, the entire size is large, and it is extremely difficult to reduce manufacturing cost of the system.